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Überseeinsel Bremen (Germany)

energetically simulated with Polysun.

Pictures: ©Überseeinsel GmbH

Thanks to its proven competence in the field of system simulation, the planning office PBS Energiesysteme was commissioned to develop the energy concept for the new harbour neighbourhood in Bremen together with Überseeinsel GmbH. This was made possible by the competent use of Polysun software.

The Überseeinsel (“overseas island”) in Bremen, Germany, is one of the largest urban development projects in Europe. A new city district is being created here on 41 hectares of land, with commercial, residential and hotel properties. Überseeinsel GmbH is to implement an energy concept that is as CO2-neutral as possible with electricity-based heating and cooling on part of the Überseeinsel, the former Kellogg production site.  PBS was commissioned to work out the feasibility of the energy system. It was clear early on that the Weser River was to be integrated as a heat source for thermal supply. The project was planned as heating network 4.0, with correspondingly clear targets set by BAFA (German Federal Office of Economics and Export Control) regarding a high share of grid feed-in from renewable sources.

Initial simulations with Polysun led to the conclusion at an early stage of the project that the Weser would not be sufficient to cover the heat demand. In a further step, PBS integrated an ice storage tank into the overall planning and defined an intelligently controlled six-loop network that includes cooling and heating with low and high temperature applications. A combined heat and power plant and a peak load boiler are planned as a reserve for peak load. The complete energy system, including the intelligent control system, was set up and energetically simulated in Polysun: “Polysun offers the greatest possible flexibility for the reliable planning of energy systems for neighbourhoods and to quickly make model adjustments”. Mr Grabowski obtains technical input from the Vela Solaris experts as required: “The exchange is uncomplicated and has always taken me one step further – that’s great!” 

Project cornerstones


Überseeinsel GmbH

Energy system components for simulation

wind energy, PV, ice storage, heat pumps, Weser river heat exchanger, six-loop network, combined heat and power plant

Vela Solaris’s service

Polysun Designer software and expert advice.


Necessary planning adjustments identified at an early stage to ensure energy requirements are met. Feasibility analysis successfully completed.


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